Does dysautonomia worsen with aging?

Does Dysautonomia Worsen with Aging?

Yes, dysautonomia typically worsens with aging due to progressive deterioration of autonomic nervous system function, leading to increased morbidity and mortality in older adults. 1

Understanding Dysautonomia and Aging

Dysautonomia refers to dysfunction of the autonomic nervous system, which can manifest in various forms:

• The term "dysautonomic" may refer to any abnormal functioning of the autonomic nervous system, encompassing different types of disorders with fundamentally different underlying mechanisms 1
• Dysautonomia can be classified into several clinical conditions including reflex syndromes, postural orthostatic tachycardia syndrome (POTS), chronic fatigue syndrome, neurogenic orthostatic hypotension (nOH), and cardiovascular autonomic neuropathy (CAN) 2

Evidence of Age-Related Worsening

The relationship between aging and dysautonomia is well-documented:

• Aging is associated with significant changes in autonomic nervous system function, resulting in an impaired ability to adapt to environmental or intrinsic visceral stimuli 3
• The degree of frailty, which increases with age, correlates with deterioration in autonomic function, particularly affecting cardiovascular regulation 1
• Age-related autonomic changes involve both parasympathetic and sympathetic alterations, leading to a higher incidence of cardiovascular disease morbidity and mortality 4

Specific Age-Related Autonomic Changes

Several specific autonomic functions show deterioration with aging:

• Cardiac function: The ability of the heart to contract deteriorates with age, and when measured against frailty index scores rather than chronological age, a linear relationship emerges where the frailest individuals exhibit the most profound dysfunction 1
• Electrical conduction: The speed of electrical impulses across the atria declines with age, an effect clearly evident in individuals with high levels of frailty, providing a substrate for arrhythmias like atrial fibrillation 1
• Blood pressure regulation: Aging is associated with increased prevalence of orthostatic hypotension, which represents a late and more severe sign of dysautonomia 2

Neurological Implications

Autonomic dysfunction also has important neurological implications as we age:

• Parasympathetic autonomic dysfunction is common in mild cognitive impairment (MCI), with MCI patients being 5.6 times more likely than controls to have autonomic dysfunction 5
• Components of the central autonomic network experience significant neurofibrillary degeneration during the course of neurodegenerative diseases like Alzheimer's 5
• Autonomic dysfunction may accelerate cognitive decline via proinflammatory mechanisms and/or hypotension-induced cerebral hypoperfusion 5

Cardiovascular Autonomic Neuropathy (CAN) and Aging

CAN represents a significant manifestation of dysautonomia that worsens with age:

• The prevalence of CAN increases with age and duration of underlying conditions like diabetes 1
• In diabetic patients, autonomic dysfunction typically progresses from involving the parasympathetic system initially, then the sympathetic system, and finally presenting as orthostatic hypotension in advanced stages 2
• CAN is associated with increased risk of myocardial infarction (which may be painless or discovered only on systematic ECG), increased cardiovascular events, and increased mortality 1

Clinical Implications and Management Considerations

The worsening of dysautonomia with age has important clinical implications:

• Patients with more severe autonomic dysfunction tend to have worse outcomes in various clinical conditions, including higher mortality rates 6
• Treatment of patients at moderate to advanced stages of dysautonomia is complex and often refractory, requiring specialized and multidisciplinary evaluation 2
• Preventive measures such as postural care, good hydration, higher salt intake, compression stockings, and supervised physical activity are important treatment steps 2

Potential Interventions

Some interventions may help mitigate the progression of dysautonomia with aging:

• Regular physical exercise appears to be effective in preventing deleterious autonomic changes associated with aging 4
• Simple strategies for autonomic function improvement include walking and somatic afferent stimulation (e.g., stroking skin or acupuncture) to increase sympathetic, parasympathetic, and central cholinergic activity 3
• Drugs that inhibit the renin-angiotensin system (e.g., angiotensin-converting enzyme inhibitors like enalapril) may reduce frailty scores in aging and potentially improve autonomic function 1